The present invention relates to a printing apparatus which is capable of two different modes of printing, i.e., printing by means of type elements, and dot-maxtrix printing with a matrix of dots.
Generally, a printing operation by means of type elements (hereinafter referred to as "type-printing") is advantageous in printing quality, but disadvantageous for its limited number of characters (letters, numerals, symbols, etc.) available and low printing speed. On the other hand, a dot-matrix printing operation has substantially no limitation in the number of characters to be printed, and is high in printing speed. However, the dot-matrix printing with these advantages suffers a comparatively low level of printing quality.
In view of such circumstances in the prior art, a printing apparatus has been proposed, which is equipped with two printing units or assemblies for performing both of type-printing and dot-matrix printing. In such a printing apparatus known in the art, however, the two printing assemblies are selectively moved, as required, into a printing position corresponding to a print line along the platen of the printer so that a printing operation is effected by the selected one of the two printing assemblies. Alternatively, the printing assembly at the printing station is changed from one to the other so that the printing is achieved by the selected printing assembly. Such printer arrangements require troublesome selective movements or changes of the two printing assemblies for one printing position.